Non-volatile storage cells are elements used widely for permanently storing data such as serial numbers, trim settings for analogue circuits, or the number of a semiconductor chip permanently in a semiconductor chip.
Documents U.S. Pat. No. 4,730,129, U.S. Pat. No. 5,404,049, U.S. Pat. No. 5,418,487, U.S. Pat. No. 5,731,733, U.S. Pat. No. 6,091,273, U.S. Pat. No. 6,384,664 B1 and U.S. Pat. No. 6,819,144 B2 describe circuit arrangements for operating non-volatile storage cells implemented in the form of a fuse.
Documents U.S. Pat. No. 6,421,293 B1 and U.S. Pat. No. 6,525,955 B1 disclose memory cells that can be programmed once only in which, during the programming, a parameter of an insulator is changed, together with an associated circuit arrangement.
Document US 2005/0212086 A1 describes an antifuse, implemented in the form of a Zener diode, which when programmed, exhibits a low value of resistance and, when not programmed, a high value of resistance.
The documents “Lifetime Study for a Polyfuse in a 0.35 μm Polycide CMOS Process”, J. Fellner, P. Bösmuller, H. Reiter, 43rd Annual IEEE International Reliability Physics Symposium, Apr. 17-21, 2005, Conference Proceedings, pages 446-449, and “A One Time Programming Cell Using More than Two Resistance Levels of a polyFuse”, J. Fellner, 27th Annual IEEE Custom Integrated Circuits Conference, Sep. 18-21, 2005, Conference Proceedings, pages 263-266, and U.S. Pat. No. 5,976,943 concern programmable resistors comprising two layers. The first layer precipitated onto the semiconductor chip comprises polysilicon, while the second layer deposited on the semiconductor chip comprises a silicide.